# CLAUDE.md

This file provides guidance to Claude Code (claude.ai/code) when working with code in this repository.

## What This Project Is

SoliCards is a native SwiftUI solitaire card game for iOS 17+, iPadOS 17+, and macOS 14+. It was ported from a web-based JavaScript game (`game-SoliCards/SoliCards.html`) following the 7-phase workflow defined in [PROMPT.md](PROMPT.md).

## Build Commands

```bash
# Generate Xcode project (required after cloning or editing project.yml)
xcodegen generate

# Build for iOS Simulator
xcodebuild build -project SoliCards.xcodeproj -scheme SoliCards -destination 'platform=iOS Simulator,name=iPhone 16'

# Build for macOS
xcodebuild build -project SoliCards.xcodeproj -scheme SoliCards -destination 'platform=macOS' CODE_SIGN_IDENTITY=- CODE_SIGNING_REQUIRED=NO

# Run tests
xcodebuild test -project SoliCards.xcodeproj -scheme SoliCardsTests -destination 'platform=iOS Simulator,name=iPhone 16'

# Static analysis
xcodebuild analyze -project SoliCards.xcodeproj -scheme SoliCards -destination 'platform=iOS Simulator,name=iPhone 16'
```

## Architecture

**MVVM + Protocol-Oriented Strategy** — see [ARCHITECTURE.md](ARCHITECTURE.md) for full details.

- `GameRules` protocol with 3 conforming structs: `KlondikeRules`, `SpiderRules`, `FreeCellRules`
- `@Observable` macro (not `ObservableObject`) for property-level SwiftUI observation
- `@MainActor` on ViewModels and TimerService for Swift 6 concurrency safety
- `DragGesture` + `PreferenceKey` frame hit-testing for card drag & drop (not `onDrag`/`onDrop`)
- SwiftData for persistence (`GameRecord`, `StatsRecord`, `PrefsRecord`)
- Zero external dependencies

## Key Conventions

- `.xcodeproj` is generated by xcodegen from `project.yml` — do not edit it by hand
- `Array.trailingSuffix(while:)` extension replaces missing stdlib `suffix(while:)` — used in rules engines for face-up card runs
- Card images are loaded from the asset catalog via platform-conditional helpers (`UIImage`/`NSImage`) in `CardView`
- Sound playback is dispatched via `nonisolated func playSound()` to avoid `@MainActor` isolation on the audio path

## Test Suite

57 tests across 12 suites. All tests are in `SoliCardsTests/` using Swift Testing (`@Test`, `#expect`).

Key test coverage areas:
- `GameEngine/` — KlondikeRules, SpiderRules, FreeCellRules, MoveValidator, AutoCompleter, GameState
- `Models/` — Card, Deck, Difficulty, GameVariant, Rank, Suit